/*

  * Copyright 2007 The Kuali Foundation

  *

  * Licensed under the Educational Community License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  * http://www.opensource.org/licenses/ecl2.php

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.kuali.rice.kew.rule;

 import java.sql.Timestamp;

 import java.util.ArrayList;

 import java.util.List;

 import java.util.Map;

 import org.kuali.rice.kew.engine.RouteContext;

 import org.kuali.rice.kew.engine.node.NodeState;

 import org.kuali.rice.kew.engine.node.RouteNode;

 import org.kuali.rice.kew.engine.node.RouteNodeInstance;

 import org.kuali.rice.kew.exception.WorkflowException;

 import org.kuali.rice.kew.routeheader.DocumentRouteHeaderValue;

 import org.kuali.rice.kew.service.KEWServiceLocator;

 import org.kuali.rice.kew.util.KEWConstants;

 import org.kuali.rice.kew.util.Utilities;

 /**

  * Rule selector that select a rule based on configured rule name 

  * @author Kuali Rice Team (rice.collab@kuali.org)

  */

 public class NamedRuleSelector implements RuleSelector {

     /**

      * The route node config param consulted to determine the rule name to select

      */

     public static final String RULE_NAME_CFG_KEY = "ruleName";

     /**

      * @return the name of the rule that should be selected

      */

     protected String getName(RouteContext context, DocumentRouteHeaderValue routeHeader,

             RouteNodeInstance nodeInstance, String selectionCriterion, Timestamp effectiveDate) throws WorkflowException {

         String ruleName = null;

         RouteNode routeNodeDef = nodeInstance.getRouteNode();

         // first check to see if there is a rule name configured on the node instance

         NodeState ns = nodeInstance.getNodeState(KEWConstants.RULE_NAME_NODE_STATE_KEY);

         if (ns != null) {

             ruleName = ns.getValue();

         } else {

             // otherwise check the node def

             Map<String, String> routeNodeConfig = Utilities.getKeyValueCollectionAsMap(routeNodeDef.getConfigParams());

             ruleName = routeNodeConfig.get(RULE_NAME_CFG_KEY);

         }

         return ruleName;

     }

     public List<Rule> selectRules(RouteContext context, DocumentRouteHeaderValue routeHeader,

             RouteNodeInstance nodeInstance, String selectionCriterion, Timestamp effectiveDate) throws WorkflowException {

         String ruleName = getName(context, routeHeader, nodeInstance, selectionCriterion, effectiveDate);

         if (ruleName == null) {

             throw new WorkflowException("No 'ruleName' configuration parameter present on route node definition: " + nodeInstance.getRouteNode());

         }

         RuleBaseValues ruleDef = KEWServiceLocator.getRuleService().getRuleByName(ruleName);

         if (ruleDef == null) {

             throw new WorkflowException("No rule found with name '" + ruleName + "'");

         }

         List<Rule> rules = new ArrayList<Rule>(1);

         rules.add(new RuleImpl(ruleDef));

         return rules;

     }

 }